GAPLESS Playback now in iPods - New!

So if it has to scan your library it's either A) adding some sort of metadata to your files or B) adding info to your library, if not both. Then, assumably, it's using said data to sort of connect the files during playback. So, in theory, it's not really playing back gaplessly in what we see as the normal fashion, but rather using a work around (?).

GAPLESS Playback now in iPods - New!

I don't know if itunes 7 fixes the recently broken DRM but if it does then it would be convenient for them to hold off on valuable updates such as gapless in order to get people to upgrade away from the cracked drm...

I have no idea if it does this as I don't have an ipod or use itunes... just a curious thought...

GAPLESS Playback now in iPods - New!

I'm testing out iTunes 7 right now with an Avalanches album, which is completely gapless. They are mp3's encoded with 3.90.3 at alt-preset standard, and they sound perfectly gapless to me, but I don't know if it is using the LAME metadata or not. The files are not modified when iTunes scans for gapless information. You do not have to check "part of a gapless album" to make it work; I don't know what that option is useful for.

GAPLESS Playback now in iPods - New!

"Some CDs, such as live concert albums and classical albums, are meant to be played straight through, with no fading between the songs (or tracks). If you turn on Crossfade Playback, you can have iTunes turn it off when you play these albums. "

apparently checking that will disable crossfading on those tracks

and i noticed after a clean install, crossfading is disabled by default in iTunes 7

I can also verify that setting "part of a gapless album" to yes has no effect if crossfading is disabled. I just ripped a live album and it played back seamlessly without that being enabled

I just tried out gapless using my 4th Generation iPod Photo, it worked perfectly on the album Blood Sugar Sex Magik by Red Hot Chili Peppers. It is an album were ALL the songs transition into each other gaplessly, and it worked great.

iTunes 7 scanned both my library on my hard disc, and my iPod the first time I connected it. However I then had to go into the iPod, select all the tracks in Blood Sugar Sex Magik, then select "Gapless Album" YES in the bottom right hand corner of the Multiple Item Information screen. As soon as I did that it rescanned the files, and made it work.

GAPLESS Playback now in iPods - New!

So if it has to scan your library it's either A) adding some sort of metadata to your files or B) adding info to your library, if not both. Then, assumably, it's using said data to sort of connect the files during playback. So, in theory, it's not really playing back gaplessly in what we see as the normal fashion, but rather using a work around (?).

Would you guys agree?

Or am I missing some prerequisite knowledge?

The normal fashion is A), adding metadata. It's just not the data in the Lame-header but in a ID3/m4a-tag field. Apart from that, the method appears the same as other (non-crossfading) gapless solutions, storing info on padding and encoder-delay in the file and using that info on playback to skip the gaps.

Last Edit: 2006-09-12 22:01:44 by Maurits

Every night with my star friends / We eat caviar and drink champagneSniffing in the VIP area / We talk about Frank SinatraDo you know Frank Sinatra? / He's dead

GAPLESS Playback now in iPods - New!

"We've added a View switch, a 3-position swtch. we've added a 2nd view called album view, so you can scroll through your music library and look at it by album. what if you ripped your CDs and don't have the covers? Today wer'e announcing free missing album cover art for all the music in your library if you have an iTunes acct. iTunes will automatically download it for free."

GAPLESS Playback now in iPods - New!

So if it has to scan your library it's either A) adding some sort of metadata to your files or B) adding info to your library, if not both. Then, assumably, it's using said data to sort of connect the files during playback. So, in theory, it's not really playing back gaplessly in what we see as the normal fashion, but rather using a work around (?).

Would you guys agree?

Or am I missing some prerequisite knowledge?

The normal fashion is A), adding metadata. It's just not the data in the Lame-header but in a ID3/m4a-tag field. Apart from that, the method appears the same as other (non-crossfading) gapless solutions, storing info on padding and encoder-delay in the file and using that info on playback to skip the gaps.

GAPLESS Playback now in iPods - New!

But this is supposed to be seamless for existing MP3s, right? So they must be using a heuristic based on the silence in the file.

I have no idea how they do it, it scans existing files and seems to work on all sorts of MP3's, regardless of original encoder.

Quote

(Obviously they don't need to do anything for M4a though.)

I've taken a peek at the metadata for a gapless-tagged M4A file and couldn't find anything out of the ordinary, so I sort of suspect they're storing it in a different file.

For m4a I expect there to be some extra info in the MOOV atom. Haven't checked it yet though.Edit: a quick peek with a Hex-editor in an iTunes analysed m4a file shows 'pgap' data in the MOOV atom. That'll be it.

Last Edit: 2006-09-12 22:22:40 by Maurits

Every night with my star friends / We eat caviar and drink champagneSniffing in the VIP area / We talk about Frank SinatraDo you know Frank Sinatra? / He's dead

GAPLESS Playback now in iPods - New!

But this is supposed to be seamless for existing MP3s, right? So they must be using a heuristic based on the silence in the file.

I have no idea how they do it, it scans existing files and seems to work on all sorts of MP3's, regardless of original encoder.

Hmmm.. I suspect they're scanning the music, determining where the ending is based on where the track suddenly becomes "all zeros" or equivalent, and then marking that point. Perhaps the same for the beginning of the track. Thus it's sort of a faux-gapless detection, because if you don't get the real gapless info at encode time, it's lost.

GAPLESS Playback now in iPods - New!

"Playing albums straight throughSome CDs, such as live concert albums and classical albums, are meant to be played straight through, with no fading between the songs (or tracks). If you turn on Crossfade Playback, you can have iTunes turn it off when you play these albums.

To override Crossfade Playback for specific songs:In iTunes, select a song and choose File > Get Info.Click Options.Select "Part of a gapless album."Tip: You can select all the songs at once (press Command as you select them), choose File > Get Info, and then choose Yes from the Gapless Album pop-up menu."

GAPLESS Playback now in iPods - New!

So, indeed iTunes does play gaplessly and cleanly (in my tests for far)... even when faking it for content that can't be gapless, like FhG encoded MP3 files. They may have gotten this right for the masses. I'd be curious on the technical details on what they are really doing.

Also, they added my beloved "Album Artist' grouping logic. FINALLY! They are using the "aART" atom for M4A files... which was documented, but not used in iTunes. For MP3 ID3v2.3 content, they use the TPE2 tag. I was already using both of these... so it "just worked."